Flexible tube and union



, April 14, 1936;

G. TABOZZI FLEXIBLE TUBE AND unxon Filed. Oct. 18, 1955 nil I PatentedApr. 14,- 1936 UNITED STATES PATENT OFFICE ammo Tam, 694 131 The presentinvention refers to improvements in fiexible'tubes and correspondingunions, especially for fuel and lubricant pipes in aeroplanes andwherever .the said pipes are exposed to 5 strong and continuousvibrations.

The flexible pipe, the object of the invention, is characterized firstlyby the fact that anordinary metallic flexible tube is covered by a band;of a material known as cellon which consists of a derivative ofcellulose chemically treated in order to make it waterproof andfireproof, hereinafter referred to as cellon or the like wound accordingto the revolutions of a helix,

each of which has a breadth equal to the lengthof all the said flexibletube that is to .say so that the revolutions of the helix of the woundcellon give rise to a species of tubewithout'solution of continuity inthe transverse direction, but they give rise only to unions in thelongitudinal direction (at the beginnng and at the end of the winding)..The tube formed by the 'ce llon tube serves as a safety tube againsteventual leakages of the liquid of the flexible metallic tube. In"

place of cellon other materials which have similar physico-chemicalproperties in'view of the special employment can be used. The safety'covering of cellor 1".or the like iscovered in its turn by a layer ofvulcanizedrubber with a view to prevent drying of the cellonand excludeexternal humidity. The said covering of rubber is subsequently coveredby a'laye'r of heat refractory material, in the form of woven mesh andvarnish (for example amianthus, amianthite, its derivatives, itssubstitutes and its compositions).

" Following this there is a covering of metallic plait.

An appropriate union for such a tube consists of a metallic tubularpiece, slightly conical, provided with helicoidal threads correspondingto 4 those of the flexible tube, of a construction known per se, so thatduring. the screwing there is a'certain tendency to expansion of thetubular portion concerned in the union, producing a watertight adherencebetween the surfaces con- 'tributingto the water tightness. In ordertorelease the said portion of the tube from the effects produced bythesaid expansion; a socket is employed which is threaded outside withexterior surface on the endv of the tubes to be Joined and its circularedge is curved against the exterior. the curve forming the seat for thethickness of the head of the tube and that by'the projecting nut,serving for the manipulation of the union.

In the accompanying drawing; the invention is shown by way of example:

Fig. 1 shows the tube with its coverings placed successively from thebeginning.

Fig. 2 shows the pertinent union to the said tube partly in section andpartly in elevation.

In the figures of the drawing l is the known 5 metallic flexible tube,which is made so due to the formation of a helicoidal groove formed by-means of filling out its walls, 2 is the covering of cellon" or othermaterial having certain physico-chemical properties according to the useto 10 which it is to be put.

The said-covering of cellon being established byva single'sheet ofcellon wound according to the revolutions of a helix eachof which has abreadth equal to the length of the flexible tube; 15

its compositions. 5 designates a metallic plait of known form and use; 6is an anti-expansive 25 metallic socket provided with a curved back end8, the width of this curve serving to forms. seat for the'thickness 1 ofthe end of the tube I, including therein all the thicknesses 2, 3, 4, 5.

In Fig. 2 is shown a conical portion of a union 30 Q provided with ahelicoidal thread of which the pitch corresponds to that of the flexibletube I.

The union is provided with a projecting nut B. The water tightness ofthe union is assured and rendered very effective by the pressure of the35 cone which acts in an expansivesense against the internal walls ofthe flexible tube, the expansive effectv being contracted by thepresence of themetallic socket 6 threaded on the head of the tube to bejoined.

40 It is to be remarked that in the metallic flexible tubes used fortheformation of the complex fiexible pipe there is inserted between theindividual layers, a thread of special celluloseor other material,insoluble and unattackable, in all cases 5 v unattackable by essence,benzol, mixtures of hy drocarbons in general, by hot oils on the like.

The-details of construction may be varied. in

order to'adapt it to different practical uses with-- out abandoning thescope of the present inven-"go I claim:

A flexible tube. and union therefore comprising a-fiexible metal tubeprovided with a helical gr oove. a band of a cellulose derivativechemically treated to render it waterproof and fireproof helically woundaround said flexible tube, a layer of vulcaniz ed rubber placed oversaid hellcally wound band, a heat resisting coating applied to saidlayer 01. vulcanized rubben, a metallic plaitedcovering placed on saidheat resisting coating, a of hollow gietal socket inserted over the endsaid plaited covering, a imion provided with a slightly conicalextension and helicoidai thread thereon, screwed into said flexibletube, at the ,end on which the socket is fitted. and said socketresisting expansion of the flexible tube.

GIACIN'IO TABOZZL

